Q14: Our sun
Q15: The strong magnetic reaction in our atmosphere
The answer is 40.
We can solve this by finding out the number of protons, and neutrons. Atomic number of an element means the number of protons in that element. So, the atom has 30 protons if the atomic number is 30.
On the other hand, mass number is the total number of protons and neutrons, but not electrons, because they're too light comparing to the other 2. Therefore, we can simply solve the number of neutrons in the atom by subtracting the number of protons from the mass number. 70 - 30 = 40.
Therfore, the number of neutrons is 40.
Answer:
255.6
Explanation:
If you have 12 gallons and get 21.3mpg,
-Multiply 21.3 by 12
-you can travel 255.6 miles before running out of gas.
-If you need to estimate, round up to 256 miles.
<u>Answer:</u> The half life of the reaction is 1190.7 seconds
<u>Explanation:</u>
The equation used to calculate rate constant from given half life for first order kinetics:

where,
k = rate constant of the reaction = 
= half life of the reaction = ?
Putting values in above equation, we get:

Hence, the half life of the reaction is 1190.7 seconds
The answer
the speed of <span>the train traveling in kilometers per minute can be found by using the following method:
v = </span><span>30 miles per hour
</span><span>1 mile = 1.6 kilometers
just do the calculus by changing miles to kilometers
</span>1 mile = 1.6 kilometers, so 30 miles= 1.6 km x 30 = 48 km
so the speed of the train is
v=30 miles / hour = 48km / h = 48km / 60 mn = 0.8 km/ mn
the answer is
<span>C- 0.8 km/min</span>